Expected Discontinuous Terrain Deformation with the Microgravity Method in a Selected Area of Shallow Coal Extraction

The results of gravimetric research in a selected area of a former coal mine “Siersza” are presented in the paper. The microgravity methods were aimed at finding the loosened zones in the near surface part of the rock mass. The physical bases of the applied method were discussed. The geological and mining conditions of the study area are outlined. The interpretation of the results of microgravity observation revealed zones of high surface deformations hazard. In one of them a discontinuous deformation occurred. The final conclusion is that the consequences of mining activity on surface may be discovered even before the surface lowering if the microgravity measurements are performed in the right time.